Monitoring Water Quality
The Water Policy Framework Regulations require that we monitor the quality of our waters on a frequent basis. The requirements are extensive and cover all surface water and groundwater bodies and Protected Areas. Monitoring programmes are required to establish a coherent and comprehensive overview of water status within each water catchment district.
There are 3 types of monitoring required for surface waters: surveillance, operational and investigative. The purposes of the monitoring types are briefly summarized in the following table:
| Monitoring | Aims |
|---|---|
| Surveillance monitoring | Validates the characterisation pressure and impact assessments Detects long-term trends Provides an assessment of overall status |
| Operational monitoring | Helps classify the status of water bodies identified as 'at risk' Assess change in status of 'at risk' water bodies that may result from the Programme of Measures. |
| Investigative monitoring | Ascertains the cause and effects of a failure to meet 'Good Status' where it is not clear Assessment of accidental pollution |
In the case of ecological status determination the following parameters need to be monitored: Â biological quality elements and supporting chemical and hydromorphological quality elements. In the case of chemical status a list of priority substances, priority hazardous substances and other substances that could potentially be of national concern are also monitored.
All these parameters are included in the monitoring programmes of the WCMP. These can be viewed in Chapter 5 of the 2nd WCMP​.
Intercalibration of Biological Quality Elements
The Directive requires that the results of national classifications are compared between different Member States in the various ecoregions of the European Union to ensure that the established class boundaries and the reported monitoring results are consistent with the normative WFD definitions, and that they are comparable between Member States. In order to achieve this, an intercalibration exercise, as referred to in Annex V of the WFD, is required between Member States. This exercise is a key element in making this general environmental objective of ‘good status’ applicable in a harmonised way throughout the EU. Its objective is to establish a common understanding of ‘good ecological status’ in all Member States that is consistent with the definitions of the Directive. Intercalibration needs to take into account current scientific knowledge about the structure and functioning of aquatic ecosystems and how human activities influence them. The results of the intercalibration exercise are expected to lead to appropriate boundary identification between the categories of high – good and good – moderate.
An intercalibration exercise on the four Biological Quality Elements for Maltese coastal waters was undertaken. The report includes:
(i) the results of the intercalibration exercise for the BQEs for which intercalibration was possible (Posidonia oceanicaand macroalgae);
(ii) data gaps and future monitoring needs for the BQEs which Intercalibration was not possible (benthic invertebrates and phytoplankton);
(iii) methods used to determine reference sites in the Maltese Islands;
(iv) approaches to intercalibration of heavily modified water bodies.
